code: def test_gluon_trainer_type():
      def check_trainer_kv_update(update_on_kv):
          x = mx.gluon.Parameter("x", shape=(10, 1), lr_mult=1.0)
          x.initialize(ctx=[mx.cpu(0), mx.cpu(1)], init="zeros")
          try:
              trainer = mx.gluon.Trainer(
                  [x],
                  "sgd",
                  {"learning_rate": 0.1},
                  kvstore=kv,
                  update_on_kvstore=update_on_kv,
              )
              trainer._init_kvstore()
              assert trainer._kv_initialized
              if update_on_kv is not None:
                  assert trainer._update_on_kvstore is update_on_kv
          except ValueError:
              assert update_on_kv is False
  
      check_trainer_kv_update(False)
      check_trainer_kv_update(True)
      check_trainer_kv_update(None)
      my_rank = kv.rank
      print(
          "worker " + str(my_rank) + " passed test_gluon_trainer_type"
      )
  
file_path: mxnet/tests/nightly/dist_device_sync_kvstore.py
imports: import sys
  import mxnet
  import numpy
  import numpy.random
  import time
label_desc: Use image node_id 5 for calling a global function with example usage: test_gluon_trainer_type() without return types